Process for preparing mordant triazol dyestuffs



Patented Dec. 17, 1946 PROCESS FOR PREPARING MORDANT TRIAZOL DYESTUFFSAchille Conzetti, Basel,

Muttenz, near Basel, Switzerland, assignors to J. R. Geigy A. G., Basel,Switzerland No Drawing. Original application October 20,

1941, Serial No. 415,822. Divided and this application June 29, 1944,Serial No. 542,822. 'In Switzerland November 26, 1940 4 Claims.

' The present application is a division of applicants} prior applicationSer. No. 415,822, filed on October 20, 1941 (Patent No. 2,362,988)

It is known that o-nitro azo dyestuffs can be converted into2-aryl-1:3-arylentriazols. Alkali sulfides and zinc-ammonia water amongothers have become known as suitable reduction agents. Such2-aryl-l:3-arylentriazols are colorless to weakly yellowish bodies whichare not dyestuffs in the technical sense.

It has now surprisingly been found that 2-aryll:3 -,ary-lentriaaolscontaining in both the aroinatlc nuclei each time in orthoorperiposition to a triazol nitrogen atom still a metallisable group areconverted in substance or on the fibre into colored complex compounds ofa mostly yellow color by treatment with metal yielding agents, such aschromium or copper yielding agents. These complex dyestuff metalcompounds are distinguished by a very good, in some cases by anexcellent light-fastness.

The new 2-aryl-.1:3-arylentriazols according to the present inventioncorrespond to the formula wherein R means an aromatic radical of thenaphthalene series, carrying the OH group in ortho position to the azogroup, dyeing wool afterchromed in yellow light-fast shades.

The above defined mordant triazol compounds are obtained by reductionofo-nitro azo dyestufis of the general formula COOH wherein R means anaromatic radical of the naphthalene series, carrying the OH group inortho position to the azo group.

For the diazo components of the o-nitro azo dyestulis the followingo-nitro amino compounds may be used: 3-nitro-2-aminobenzoic acid,3-nitro-2-amino-benzoic-5-sulfonic acid (obtained by sulfonatingo-chlorobenzoic acid with oleum, nitrating the chlorosulfobenzoic acidwith nitric acid-sulfuric acid mixture and heating the obtained3-nitro-2-aminobenzoic-S-sulfonic acid with ammonia water in a closedvessel up to a and Otto Schmid,

2 higher temperature) 3 :5-dinitroe2-aminobenzoic acid and so on. Ascoupling components are suitable for instance: fi-naphthol, l-hydroxyenaphthaleneland -5-sulfonic acid, Z-hydroxy naphthalene-4-., -5-, -6-,-'7- or 8-sulfonic acid, amino or acylaminonaphthol sulfonic acids re;-spectively coupling in o-position to the hydroxyl group.

The reduction of the o-nitro azo dyestuffs to the corresponding triazolcompounds is carried out in known manner by a treatment with alkalisulfide in an aqueous solution at a raised temperature, e. g. at 80-100C., or with zinc dust in ammonia water also at a raised temperature. Insome cases it is advantageous for the sulfide reduction to complete thereaction by adding little quantities of stronger reduction agents, suchas sodium hydrosulfide 0r zinc and hydrochloric acid.

When applied from an acid bath, the metalfree triazols have an excellentaflinity to animal fibres and give uniform chromium dyeings of highfastness properties to light by a treatment with compounds of the6-valent chromium. By means of coppering mostly yellow colored pigmentsof high fastness to light are obtained.

The products obtainable according to this method are mostly more or lessyellow colored powders which; when applied from an acid bath, yieldcolorless or yellowish colorations on. animal fibres and give, bytreatment with metal yielding agents, such as for example chromiumsalts, strong colorations of yellow to brownish yellow dyeings. The sameare distinguished by good, in some cases even by excellent fastnessproperties to light.

The present invention is illustrated by the following example, whereinthe parts are by weight.

EXAMPLE 46.1 parts of the o-nitro dyestuif obtainable from diaz'otized3-nitro-2amino-5-sulfobenzoic acid and c-naphthol, are dissolved in 450parts of hot water and, whilst stirring, 30 parts of an ammonium sulfidesolution (corresponding to 6.8 parts (NI-102s) dropped at 80-90 G. intothe red orange solution. Under separation of sulfur the solution becomesorange yellow colored. It is clarified and treated at 50-60 C. with thenecessary quantity of sodium hydrosulfite required for obtaining a pureyellow final color of the solution (consumption 10-12 parts ofhydrosulfite) Then the whole is still maintained for 30 minutes at C.,acidified with 35 parts of concentrated hydrochloric acid and heated up.

The dyestuif dyes wool from an acid bath with yellowish shades which bytreatment with salts of hexayalent chromium change into strong reddishyellow dyeings of good fastness.

a ate? 4 taining a sulfonic acid group and corresponding to'the formulaCOOH 0H HOaS N02 3. Process for the manufacture of mordant Table 1" t dC I f Shade of wool dyeing rea e 0 or o No. o-Nitro azo dyestufi with;the powder 7 Acid Chromed 1 3-nitro-2-amino-benzoic acid1'hydroxynaphthaleneA-sulfonic acid. (NHmSm Yellow Yellowish...Reddish-yellow. 3-nitro-2-amino-benzoicacidl-hydroxynaphthalene-5-su.lfonicacid. do do .do Do.3-nitro-2-amin0-benzoicacid 2-hydroxynaphthalene-4-sulfonicacid. do do--do Do. 4 R-nitro-Z-amino-benzoicacid2-hydroxynaphthalene-fi-sulfonicacid. do .do .do Do.

' 3:5-dinitro-2-aminobenzoic acid 'yields similar dyestuffs with thecoupling components cited in the dyestuffs Nos. 1 to 4 of the foregoingtable, also when in the above dyestuffs the 2-hydroxynaphtha1ene-4- and-6-sulfonic acid is replaced by the corresponding -5-, -'7- and-8-sulfonic acid.

What We claim is: s

1. Process for the manufacture of mordant dyestuffs of the2-ary1-1z3-arylentriazol series, comprising reducing an o-nitro azodyestuff containing a 'sulfonic acid group and corresponding to theformula coon I l l N=N-R 'wherein "R means an aromatic radical of thenaphthalene series, carrying the OH group in ortho-position to the azogroup.

'2. Process for the manufacture of a mordant dyestuff of the2-aryl-1z3-arylentriazol series, comprising reducing an o-nitroazodyestufi condyestuffs of the 2-ary1-1:3-arylentriazol series,

comprising reducing an o-nitro azo dyestuff containing a sulfonic acidgroup and corresponding to the formula COOH COOH OH ACHILLE CONZETTI.OTTO SCHMID.

